剑指offer (42) 单词翻转

void reverse(char* first, char* last)
{
    assert(first != NULL && last != NULL);
    while (first < last) {
        char temp = *first;
        *first = *last;
        *last = temp;
        ++first;
        --last;
    }
}

void reverseTotal(char* str)
{
    assert(str != NULL);

    char* first = str;
    char* last  = str;
    while (*last != ‘\0‘) {
        ++last;
    }
    --last;
    reverse(first, last);

    first = str;
    last = str;

   // 以空格为分隔符解析单词
    while (*first != ‘\0‘) {
        if (*first == ‘ ‘) {
            ++first;
            ++last;
        } else if (*last == ‘ ‘ || *last == ‘\0‘) {
            reverse(first, --last);
            ++last;
            first = last;
        } else {
            ++last;
        }
    }
}